/*
We are given head, the head node of a linked list containing unique integer values.

We are also given the list G, a subset of the values in the linked list.

Return the number of connected components in G, where two values are connected if they appear consecutively in the linked list.

Example 1:

Input:
head: 0->1->2->3
G = [0, 1, 3]
Output: 2
Explanation:
0 and 1 are connected, so [0, 1] and [3] are the two connected components.

Example 2:

Input:
head: 0->1->2->3->4
G = [0, 3, 1, 4]
Output: 2
Explanation:
0 and 1 are connected, 3 and 4 are connected, so [0, 1] and [3, 4] are the two connected components.

Note:

    If N is the length of the linked list given by head, 1 <= N <= 10000.
    The value of each node in the linked list will be in the range [0, N - 1].
    1 <= G.length <= 10000.
    G is a subset of all values in the linked list.


 */

class Solution {
    public int numComponents(ListNode head, int[] G) {
        Set<Integer> set = new HashSet<>();
        for (int i : G) {
            set.add(i);
        }
        int count = 0;
        while (head != null) {
            ListNode cur = head;
            boolean found = false;
            while (cur != null && set.contains(cur.val)) {
                found = true;
                cur = cur.next;
            }
            if (found) {
                count++;
            }
            head = cur == null ? cur : cur.next;
        }
        return count;
    }
}